JRMC diverted ambulances after losing power Monday.
According to JRMC, a failure occurred in an Entergy utility feed. The resulting power loss affected air chillers that power the north section of the building and emergency room.
The hospital says the operating rooms were also without power.
Approximately 20 patients in affected areas have been moved to other areas of the building for their comfort and safety.
Patients and all ambulances to the emergency room were diverted to other facilities.
Hospital and Entergy staff worked throughout the night.
Entergy anticipates power to be restored by mid-morning on Tuesday.